Method and apparatus for recording signals with sub-signals indicative of outline of the signals

ABSTRACT

A disc recording/playback apparatus adapted to obtain data of recorded signals at the maximum level within a predetermined period in the signal recorded on an erasable medium per each predetermined period from a signal recording start point to end point and to record them as waveform data of the recorded signal in a different recording area from that of the recorded signal. A compressed envelope waveform of the recorded signal may be displayed on a display section by supplying the waveform data continuously to the display section, so that broad signal changes can be understood by viewing them.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a disc recording/playback apparatussuitably applied to a master disc unit for producing a cutting masterdisc which is an original disc used for manufacturing a large number ofcompact discs (CD) and mini-discs (MD) in a music disc manufacturingfactory and more particularly to a disc recording/playback apparatusadapted to be able to display a compressed envelope waveform of musicsignal to be recorded.

2. Description of the Related Art

A recording medium for a cutting master which is an original disc ofcompact discs and mini-discs has to be provided in manufacturing a largenumber of compact discs and mini-discs in a music disc manufacturingfactory. Normally a magnetic tape is used for this recording medium.FIG. 36 is a system block diagram of a main part of a prior art masterrecording apparatus 10 used for creating the original disc.

In FIG. 36, normally a digital video tape recorder (U-matic video taperecorder) is used in a multi-channel tape recorder 11 in which sourcemusic signals are recorded to create an original audio tape in which themusic signals are recorded. Because the original audio tape ismulti-channel recorded, a master recorder 12 converts it into twochannel signals.

A master tape is then supplied to an editing unit 13 to implementediting operations necessary for convertion into a format conforming tothe type of disc to be cut to create a final master tape for cutting.All disc manufacturing factories produce corresponding compact discs andcassette tapes using this master tape.

Incidentally, with the recent spread of music discs, the demand forusing discs as recording mediums for original discs has strengthened. Byusing the disc as an original, original signals can be recorded linearlywithout compressing them and edited on one original disc withoutdestroying them, making the disc an original.

In using the disc as the original instead of the tape described above,it is helpful in editing operations, such as determining editing points,if broad envelope changes of music signals recorded in the disc can begrasped when carrying out editing operations using the disc.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a discrecording/reproducing apparatus adapted to facilitate capturing arecorded signal by recording a compressed envelope waveform of thesignal recorded in the disc in a different area from that of therecorded signal.

In order to solve the aforementioned problem, a disc recording/playbackapparatus of the present invention is adapted to obtain data of amaximum level recorded signal within a predetermined period in thesignal recorded on an erasable medium per each predetermined period froma signal recording start time to end time, and to record the data aswaveform data of the recorded signal in a different recording area fromthat of the recorded signal.

For example, as shown in FIG. 14A, wherein audio data is shown asanalog, data of a maximum level recorded signal within a predeterminedperiod T is obtained in the signal recorded on the erasable disc pereach predetermined period from the signal recording start time to endtime and they are recorded as waveform data (FIG. 14B) of the recordedsignal in a different recording area from that of the recorded signal.

A compressed envelope waveform (FIG. 14B) of the recorded signal may bedisplayed on a display section by supplying the waveform datacontinuously to the display section, so that broad signal changes can beunderstood by viewing them.

The above and other advantages of the present invention will become moreapparent in the following description and the accompanying drawings, inwhich like numerals refer to like parts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram showing the main parts of a master recordingapparatus;

FIG. 2 is a drawing showing an outline of a pickup system and headsystem;

FIG. 3 is a section view of a disc;

FIG. 4 is a section view of part of a disc;

FIG. 5A-D are diagrams showing a relationship between absolute addressesand data;

FIG. 6 is a perspective view showing a main part of concrete example ofa light pick-up unit;

FIG. 7 is a perspective view showing one example of a disc storing case;

FIG. 8 is a section view of a main part of an erroneous erase preventionmeans;

FIG. 9 is a plan view showing one example of the erroneous eraseprevention means;

FIG. 10 is a rear view of the erroneous erase prevention means in FIG.9;

FIG. 11 is a table showing one example of contents recorded in asub-data area;

FIG. 12 is a system diagram showing one example of a signal processorused in a disc recording unit;

FIGS. 13A, 13B, 13C and 13D are explanatory diagrams of programreproducing modes;

FIG. 14A is an explanatory diagram showing sampled waveform data;

FIG. 14B is an explanatory diagram showing a recording example of thewaveform data;

FIG. 15 is an explanatory diagram showing a data bit display example;

FIG. 16 is a system diagram showing one example of a display elementdriving circuit for realizing the display of data bits;

FIG. 17 is a system diagram showing one example of a recording/playbackprocessing section used in the disc recording unit;

FIGS. 18A through 18D are diagrams for explaining a REC monitor;

FIG. 19 is a flowchart of the REC monitor;

FIG. 20 is a diagram explaining operations of the REC monitor on a disc;

FIG. 21 is a block diagram of a variable oscillating circuit usable as aclock generating circuit;

FIGS. 22A through 22C are diagrams for explaining SYNC REC;

FIG. 23 is a flowchart of the SYNC REC;

FIG. 24 is a flowchart showing one exemplary process for registering adisc ID;

FIG. 25 is a flowchart showing an exemplary process for recording editdata and the like;

FIG. 26 is flowchart showing another exemplary process for recordingedit data and the like;

FIG. 27 is a flowchart showing an exemplary process for conversion totime codes;

FIG. 28 is a diagram for explaining the conversion to time codes;

FIG. 29 is another diagram for explaining the conversion to time codes;

FIG. 30 is a flowchart showing one exemplary process for checking thedisc;

FIG. 31 is a flowchart of a process for recording waveform data;

FIGS. 32A and 32B are diagrams for explaining a recorded data optimizingprocess;

FIG. 33 is a diagram for explaining the edit data used in the optimizingprocess;

FIG. 34 is a flowchart showing one example of the recorded dataoptimizing process;

FIG. 35 is flowchart showing another example of the recorded dataoptimizing process; and

FIG. 36 is a block diagram of a prior art master recording apparatus.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to the drawings, a preferred embodiment of a discrecording/playback apparatus of the present invention will be explainedin detail concerning a case when it is applied to the master recordingapparatus described above.

FIG. 1 is a system diagram showing an outline of a master recordingapparatus 10 wherein original audio signals are input to a signalprocessor 100 and audio data (REC data) and the like processed accordingto their purpose are supplied to a recording/playback processing system200 in the next stage to be recorded on a disc 300 provided therein.

The disc 300 is an erasable disc and serves as an original disc, i.e. amaster disc for cutting. Audio data recorded in the disc 300 may beedited without being destroyed. This will be described later in detail.

A main control section (main CPU) 400 controls the signal processor 100and another control section (CPU) 500 controls the recording/playbackprocessing system 200. Because the CPU 500 mainly controls the servosystem of the disc 300, it will be referred to as a servo CPUhereinafter. The main CPU 400 and servo CPU 500 are adapted to operatesynchronously with each other by being linked through a SCSI interface.

FIG. 2 shows an outline of a system for recording/reproducing audio datato/from the disc 300 for which a magneto-optical disc (MO disc),described later, is used. A light pick-up unit 310 utilizing a laserbeam is provided on one side of the disc 300 and a magnetic head unit230 forming a recording system is provided on the other side thereof.The erasable disc need not be confined to a magneto-optical disc.

Digitized audio data (including data accompanying the audio datadescribed later) is supplied to a terminal 231. It is then supplied to amagnetic head 233 via a head driver 232 to write the audio data incooperation with the light pick-up unit 310.

A gap sensor 234 is provided within the magnetic head unit 230 to beable to scan the disc 300 without coming into contact therewith. The gapsensor 234 and the disc 300 are arranged so that they form a pair ofelectrodes, and the magnetic head unit 230 is controlled so that a gap Ltherebetween is kept constant based on changes of electrostatic capacitydetected by the gap sensor.

The disc 300 utilizes the structure shown in FIG. 3. As shown in FIG. 4in detail, pre-grooves (guide grooves) 303 wobbled by FM-modulatingabsolute addresses are formed across a predetermined area at apredetermined position under a disc substrate (disc) 301 and amagneto-optical film (MO film) having a much larger area than that ofthe pre-grooves 303 is coated so as to cover the surface of thepre-grooves 303. The reference numeral 302 denotes a hole for chucking.

As is well known, the magneto-optical film 304 is magnetized in thedirection of an external magnetic field applied thereon when a specificpoint is heated to more than a predetermined temperature. The heating upto more than the predetermined temperature is realized by radiating alaser beam, the power of the laser being controlled so that it isstronger when writing audio data than when reading it. The surface ofthe magneto-optical film 304 is covered by a protection film 305.

With reference to FIGS. 5A through 5D, absolute addresses (AAIP)pre-striped in the pre-grooves 303 will be explained. The absoluteaddresses are FM-modulated and recorded in the pre-grooves 303 in blockunits as shown in FIG. 5B. The absolute address is a pre-masteredaddress. The same address data is repeated 5 times and recorded in oneblock as shown in FIG. 5C.

One block of audio data is defined as having the same length as oneblock of the absolute address, as shown in FIG. 5D, and 105 frame dataare stored in one block. Among 105 frames, 98 frames are frames foraudio data and 5 fames of preamble area are held at the front portion ofthe block while 2 frames of postamble area are held at the rear portionof the block.

The absolute addresses affixed to a main data area MA are recorded sothat their frame numbers progress in the direction from the innerperiphery side to the outer periphery side of the disc, and the absoluteaddresses affixed to a sub-data area SA are recorded so that theirnumbers progress in the direction from the outer periphery side to theinner periphery side thereof.

The light pick-up unit 310 for reading the audio data is constructed asshown in FIG. 6. A light pick-up unit used in practice in the lightpick-up system of compact disc players and the like may be appropriatedfor use in the major part of the light pick-up unit 310.

Laser light (laser beam) obtained from a laser beam source 601 through acollimator lens 602 is diffracted by a grating 603 to be divided into aplurality of laser beams. It is divided into at least three beams inthis example to extract signals, to detect tracking errors and tocontrol focus. The divided laser beams are radiated onto the disc 300through a beam splitter 604, phase mirror 605 and objective lens 606.

The laser beam (return beam) reflected from the disc 300 is input to thebeam splitter 604. The laser beam transmitted through the beam splitter604 is then input to a beam splitter 610 through a half wave plate 607,converging lens 608 and multi-lens 609. The laser beam reflected by thebeam splitter 610 is image-formed on a first optical detecting element611 and the laser beam transmitted through the beam splitter 610 isimage-formed on a second optical detecting element 612.

The first and second optical detecting elements 611 and 612 may becomposed of a plurality of detecting elements whose optical detectingsurfaces are divided into a plurality of parts, and the output obtainedfrom each is added/subtracted to detect audio data (RF signals),tracking errors and focus errors.

A photo detector 613 provided at the end surface of the beam splitter604 serves as a means for detecting a quantity of light for APC forautomatically controlling the power of the laser light source 601.

The erasable disc 300 is used in a state where it is stored in a flatcase similarly to a compact disc or the like. FIG. 7 is a perspectiveview of a disc storing case 240 which is one example of the above flatcase.

As seen in FIG. 7, the storing case 240 is composed of a flat upper case241 and lower case 242. Window holes 243 and 244 having a predeterminedsize are created at a predetermined position of the upper and lowersurfaces of the cases in a state when they are combined. Normally ashutter 245 is closed to protect the disc 300 stored inside from dustand the like. The shutter 245 is opened as shown in FIG. 7 when audiodata is recorded or reproduced. The lock of the shutter 245 is releasedby a releasing projection attached at a concave portion 246 created atthe front of the case. The lock is released when the case is loaded intoa main body of the apparatus (an explanation of this function is omittedhere since a conventional mechanism is appropriated for the purpose).

Channels 247 and 248 created at the front portion of the sides of thecase are channels for guiding the case during loading. A concave section249 provided at an edge portion of the front of the case serves as ameans for preventing the case from being erroneously inserted. Itfacilitates discrimination of a 5.25 inch size MO disc, often used forsaving data for computers. In order to prevent it from being erroneouslyinserted, the storing case is designed to have a size larger than thatof existing MO discs.

One surface of the upper case 241 is provided as a label area 250. Thereference numeral 251 denotes a hole (reference hole) for positioningthe created case through the lower case 242, and 252 denotes a hole fordetecting the type of created disc similarly through the lower case 242.The disc type may be accommodated to types of cutting master discs or totypes of discs such as read only, write-once or erasable discs.

Concave portions 253 and 254 having respective predetermined widths areprovided at the rear portion of the sides of the case to use as engagingconcave portions for carrying the loaded case to another location.

Erroneous erase prevention means 260 is provided at the side of the rearportion of the case. Because the main data area MA and sub-data area SAare in the programmable area of the disc 300 described above and datamay be recorded into each area, the erroneous erase prevention means 260must be devised to be able to prevent erroneous erasure in any area.

The erroneous erase prevention means 260 may be switched among threestages. The first stage is a mode by which data can be freely rewrittenin both the main data area MA and sub-data area SA.

The second stage is a mode by which erroneous erasure of the main dataarea MA is prevented. Accordingly, the sub-data area SA may be freelyrewritten in this second stage. The third stage is a mode by whicherroneous erasure is also prevented in the sub-data area SA as well asthe main data area MA.

Data in the programmable area may be securely protected according to thepurpose of the user by preventing erroneous erasure by dividing it thusinto three stages. In order to achieve such stepwise prevention oferroneous erasure, the erroneous erase prevention means 260 isconstructed as shown in FIGS. 8, 9 and 10.

FIG. 8 is a section view of the erroneous erase prevention means, FIG. 9is a plan view of the erroneous erase prevention means seen from thesurface of the disc and FIG. 10 is a rear view of the erroneous eraseprevention means seen from the rear of the disc.

In the erroneous erase prevention means 260, a slide hole 261 (see FIG.9) having a predetermined width is perforated on the upper case 241 asshown in FIG. 8 and a slide hole 262 having a predetermined width isperforated also through the lower case 242 at a position substantiallyinward from the hole 261. A guide plate 263 is provided so as to projectinward from the upper case 241 as shown in FIG. 8 to allow an erroneouserase prevention claw 264 to slide along the guide plate 263.

The erroneous erase prevention claw 264 has a main body 265 having aslide concave portion 265a which accommodates the guide plate 263. Apositioning piece 266 is provided at the upper end portion of the mainbody 265 so as to project upward and a detecting projection 267 isprovided at the lower end portion thereof so as to project downward. Inthis example, the detecting projection 267 is positioned toward theinside of the case by a predetermined length from the positioning piece266. A projection 268 secures the slide position of the main body 265 atthree positions and corresponding concave portions 261a are provided atthe three corresponding positions of the upper case 241.

A detecting sensor 270 is mounted and secured on a board 273 of the mainbody of the apparatus so that it faces the slide hole 262. The detectingsensor 270 is provided with three detectors 271a, 271b and 271c, as willbe described later, to be able to detect the slide position of theerroneous erase prevention claw 264 from states of abutment of thosedetectors.

In the changeover state in FIG. 8, the positioning piece 266 is locatedat the position shown in FIG. 9 when seen from the upper surface of thedisc and the detecting projection 267 is located at this time at theposition shown in FIG. 10 seen from the back of the disc. Thischangeover state shall be defined as a first change-over state. In FIG.9, a second changeover state is brought about when the positioning piece266 is moved toward the left by one step, and a third changeover step isbrought about when it is moved further toward the left by one step.

The detected output of the detecting sensor 270 shown in FIG. 8 issupplied to the servo CPU 500 to generate a record inhibiting signalcorresponding to the detected output and to thereby control the magnetichead unit 230 and light pick-up unit 310 to be set in the erroneouserase prevention mode corresponding to each of the changeover steps.

While the area of the magneto-optical film 304 is the data recordingarea (program area), a given area from the outer periphery to the innerperiphery in the program area is secured as the main data area MA and agiven area further inside from the main data area MA is secured as thesub-data area SA.

Audio data per se is recorded in the main data area MA and discmanagement information and the like as well as data accompanying therecorded audio data is recorded in the sub-data area SA. FIG. 11 showstypical data recorded in the sub-data area. Among those data, a discidentification code (disc ID) is an identification code unique to thedisc itself. An explanation of waveform data will be made later.

FIG. 12 shows an embodiment of the signal processor 100. An analog audiosignal is supplied to a terminal 101 and is converted into a digitalsignal in an A/D converter 102. A digital audio signal is supplied to aterminal 103 and is supplied to a digital interface circuit 104. Eitherinput of the digitized audio signals is selected by a switch 105 and isthen supplied to a fade control circuit (cross-fader) 110.

The fade control circuit 110 is a processing system for realizingcross-fading such as fade-in and fade-out of audio signals and comprisesa digital signal processor (DSP) 111, temporary RAM 112 for thecross-fade process and RAM 113 for sub-data for temporary storingcross-fade processing information.

The cross-faded digital audio signal is output to an output terminal 107via an encoder 106 and is supplied to the magnetic head unit 230 asaudio data.

Audio data read out by the light pick-up unit 310 is supplied to aninput terminal 120 via the recording/playback processing system 200. Adecoder 121 decodes the audio data and an error correcting process isperformed on the data using a temporary RAM 122. After undergoing thisprocess, the audio data is supplied to the fade control circuit 110 orto another fade control circuit 130 for reproducing programs in the caseof reproducing a program.

The fade control circuit 130 comprises an input changeover switch 131,and pair of buffer memories 132 and 133 and DSP 134. The changeoverswitch 131 selects either the output of the decoder 121 or audio datafrom another unit supplied to a SCSI communication interface 125 from aninput terminal 124.

The fade control circuit 130 is designed to allow cross-fading of randomaudio data a, b and c on the disc 300 as shown in FIG. 13A, for example,in a state programmed as shown in FIGS. 13B or 13C. At this time, anappropriate pause period may be inserted between the audio data as shownin FIG. 13D. The pause period may be fixed or controlled by the user.

The program-reproduced audio data after the cross-fade process is inputto the fade control circuit 110 via a changeover switch 135. The fadecontrol circuit 110 is controlled so that it is in a simple throughstate in the case of program-reproduced audio data.

The output thereof is converted into an analog signal by a D/A converter136 and is directed to a terminal 137 or a terminal 139 in its digitalsignal state directly through a digital interface circuit 138.

A terminal 140 is an input terminal of time codes TC supplied asnecessary. When a time code TC is input thereto, it is directed to theencoder 106 via an interface circuit 141 and changeover switch 142 andis recorded in the main data area MA together with the audio data. Thetime code TC output from the decoder 121 is output to an externalterminal 145 via the change-over switch 142 and interface circuit 144.

The main CPU 400 controls various signal processings necessary in thesignal processor 100 such as the cross-fade process described above andalso controls a waveform data processing circuit 151. The waveform dataprocessing circuit 151 has a waveform editing function by which audiodata is sampled at predetermined intervals to accumulate waveform data.A RAM 152 is a temporary RAM used at such a time. The waveform dataaccumulated in the RAM 152 is also stored in a RAM for sub-data 113.

FIGS. 14A and 14B show examples of edited waveform data. As shown in thefigures, maximum values of the original audio data is obtained within apredetermined period T and accumulated from the start to end ofrecording to be recorded in the sub-data area SA as waveform data.

It is possible to roughly grasp what kind of audio data is recorded bycontinuously observing the waveform data. The waveform data may bedisplayed on a display section 153 by reading them out from the RAM forsub-data 113 after recording the audio data and supplying it to thedisplay section 153. Moreover, because it may be reproduced from thesub-data area of the disc 300 at any time, the reproduced waveform datamay be displayed at any time by storing it in the RAM for sub-data 113and supplying it to the display section 153.

A level indicating section as shown in FIG. 15 is provided in part ofthe display section 153. The level indicating section is adapted to beable to indicate two channels, each of which is composed of a pluralityof display elements 181 (24 display elements in this example) arrangedlinearly. A display element 182 indicates an over-level.

24 display elements 181 are used to enable the level indicating section180 to display even the maximum quantized number of bits of input audiodata. This is because the quantized number of bits differs as 24 bits,20 bits and 16 bits depending on sampling frequencies used, becausethree kinds of sampling frequencies (48 KHz, 44.1 KHz and 44.056 KHz)used in sampling are provided.

The display elements 181 and bit are related such that the left portionof the display elements indicates a MSB and the right portion elementsdisplay lower bits. The 16 th display element will indicate a LSB whenthe quantized number of bits is 16 bits and in the same manner, the 20th element will indicate a LSB when the number is 20 bits and the 24 thelement will indicate a LSB when the number is 24 bits.

FIG. 16 shows a concrete example of a display element driving circuit185 contained in the display section 153 for indicating the bits.

The waveform data input to a terminal 186 from the RAM for sub-data 113via the main CPU 400 is supplied to a shift register 187 composed ofeight steps and is sequentially shifted bit by bit by a shift clock (bitclock) from a terminal 190. Three shift registers which arecascade-connected are used. The first input bit of the shift register187 will be the LSB and the final input bit will be the MSB. Bit outputof each of the shift registers 187,188 and 189 are latched concurrentlyby latch circuits 191, 192 and 193 respectively and supplied to thecorresponding display element 181 via drivers 194,195 and 196. Bits maybe displayed corresponding to the input number of bits as shown in FIG.15 by constructing the driving circuit as described above. Further, suchwaveform data may be output to an external device.

Returning to FIG. 12, the signal processor 100 will be explainedfurther. Alarm means 154 provided in connection with the main CPU 400gives an alarm to the user when a data error is brought about due toadhesion of dust and the like during the disc check described later.Details thereof will be explained later.

A ROM 155 stores control programs and the like necessary for performingsignal processing. The sub-data information and the like temporarystored in the temporary RAM 113 and the like are finally stored in theRAM 156.

A keyboard 170 is operated by the user and an interface circuit 171serves as an interface used when communicating with the servo CPU 500.

FIG. 17 shows a concrete example of the recording/playback processingsystem 200. The audio data output from the encoder 106 is supplied to abuffer memory 202 arranged in FIFO and when the predetermined number ofblocks of audio data are stored, it is read at a faster speed than thewriting speed to the buffer memory 202. The reading speed is set to beat least 2.5 times the writing speed which is defined as a standardreference speed. The writing speed is adjusted by adjusting the rotatingspeed of the disc. It is 2.5 times the speed in the embodiment. That is,the rotating speed of the disc is set to be 2.5 times its normalrotating speed. 3 times the writing speed may be also an adequate value.The disc 300 is accessed at such high speed in order to realize a REC(record) monitor using a single pick-up system as described later.

The audio data read out at 2.5 times speed is supplied to the magnetichead unit 230 via a head driver 232 to be recorded. A gap servo circuit203 keeps the gap length of the magnetic head unit 230 constant.

The audio data recorded in the disc 300 is read (reproduced) by thelight pick-up unit 310. Reading speed at this time is 2.5 times speed,the same as the writing speed. The waveform of the reproduced output isshaped by an equalizer circuit 211 and absolute addresses contained inthe reproduced output are supplied to a PLL circuit 212 to generate areproduction clock.

Based on the reproduction clock, the reproduced output data the waveformof which has been shaped is supplied and stored in a buffer memory 213arranged in a FIFO format. Data reading speed from the buffer memory 213is standard speed and data read out is supplied to the decoder 121.

This is for the purpose of realizing the REC monitor and the like by onelaser beam as described above to perform such signal processing aswriting the audio data output from the signal processor 100 into thedisc 300 at 2.5 times transfer speed, reading out at the same speed andreturning the speed to the original standard speed when supplying to thesignal processor 100.

With reference to timing charts in FIGS. 18A, 18B, 18C and 18D and aflowchart in FIG. 19, the REC monitor will be explained in detail. Whenthe audio data is written into the disc 300 at the writing speed of 2.5times speed, a read mode starts at a stage where three blocks of audiodata are stored in the buffer memory 202 (Step 351). Then, arelationship between a time axis of the original audio data and that ofthe audio data read from the buffer memory 202 is as shown in FIGS. 18Aand 18B and the writing of the three blocks of audio data into the disc300 is finished with a little over one block of the original audio data(Step 352).

When writing is finished, the light pick-up unit 310 accesses at highspeed (seeks at high speed) the head address of the audio data mostrecently written (Step 353) and immediately after that, the mode istransferred to the read mode (Step 354). Because the reading speed andwriting speed are both 2.5 times speed, the reading of three blocks ofaudio data is finished at the same time as the writing time (FIG. 18C).The read out audio data is written into the buffer memory 213 at thesame time (Step 355).

Because the combined time of the audio data writing time to the disc andreading time from the disc is shorter than the time of the threeoriginal blocks, the light pick-up unit 310 may immediately access therear end data of the audio data most recently written at a stage wherethe reading of the audio data is finished as shown in FIG. 18B so as tobe ready for writing the next audio data (4 through 6 blocks) (Step352).

On the other hand, because the audio data is read into the buffer memory213 in a state in which its time axis is returned to the original timeaxis (Step 356), the audio data just written may be monitored at thesame time as the next audio data is written.

FIG. 20 is a diagram for conceptually explaining the above wherein theaudio data writing operation and REC monitor operation are performedconcurrently by repeating a the writing process and reading process ofthe audio data into/from the disc 300.

Returning again to FIG. 17, the recording/play-back processing system200 will be further explained. The light pick-up unit 310 detects notonly signal components but also tracking signals and focus signals. Theyare supplied to a focus error and tracking error detecting circuit 215wherein tracking error and focus error are detected independently ofeach other and those error signals are fed back to a tracking controlcircuit and focus adjusting circuit (both not shown) provided within thelight pick-up unit 310 so that those error signals are zeroed.

The tracking signal is also supplied to an absolute address detectingcircuit 216. Because the absolute address is wobbled, the brightness ofthe laser beam reflected from the disc is modulated by the absoluteaddress. Then the absolute address may be detected from the modulatedoutput. Since the absolute address also signals the rotating speed ofthe disc 300, a servo circuit 217 of a spindle motor 218 is controlledbased thereon to keep the disc rotating speed (e.g. linear velocity CLV)constant.

The absolute address is supplied to the main CPU 400 via the servo CPU500 to be converted into time code TC of SMPTE and the like. Theabsolute address is also supplied to an address checking circuit 221 tobe used as judgment data for checking disc errors which will bedescribed below.

The disc error check is carried out to prevent from occurring beforehandsuch trouble as causes an error to be brought about in writing or databeing unable to be correctly read due to dust and the like adhering tothe disc when in use. The tracking error has to be detected to carry outthe disc error check. The reference numeral (220) denotes a trackingerror detecting circuit and its output is supplied to the servo CPU 500.Details of the disc error check will be described later.

The reference numeral (700) denotes a variable oscillating circuit usedas a clock generating circuit. The clock is supplied to the buffermemory 202 and spindle motor 217 in the recording system as theirreference signal. Because the clock frequency used differs depending onthe quantized number of bits of audio data and because the audio dataneeds to be edited while being reproduced at variable speed, thevariable oscillating circuit 700 is constructed as shown in FIG. 21.

A quartz oscillator or the like whose oscillating output is stable isused as an oscillating source of a reference quartz oscillator 701. Thereference oscillating output is divided into 1/n (n: integer) by adivider 702 and the divided output is supplied to a phase comparator703. The reference numeral (704) denotes a voltage-controlled oscillator(VCO) using a voltage controlling system or the like. Its output is usedas the clock and is supplied to a variable divider 705 to be divided inaccordance with a dividing ratio specified by the servo CPU 500.

The divided output is compared with the reference divided output by thephase comparator 703 and the output thereof is supplied to the VCO 704via a low-pass filter 706 to control PLL so that the VCO 704 oscillateswith a clock frequency set by the servo CPU 500. The oscillating outputis output via a switch 707.

The oscillating output of the reference oscillator 701 is also suppliedto the switch 707 and is used when the VCO 704 is controlled so that itoscillates the reference oscillating output (f0'=f0).

A certain degree of jitter is brought about in the VCO 704 because it iscomposed of a LC circuit or the like. The jitter leads to thedegradation of reproduced sound quality. The reference oscillator 701produces much less jitter compared to the VCO 704 because a quartzoscillator having high stability is used. Accordingly, the switch 707 isprovided in considering that a higher reproduced sound quality may beobtained by using the oscillating output of the reference oscillator 701when the VCO 704 is controlled to output the reference oscillatingfrequency. Whether the reference oscillating output is selected or notis controlled by the servo CPU 500 and a switch controlling signal issupplied from the servo CPU 500.

FIGS. 22A, 22B and 22C are diagrams for explaining SYNC REC mode. TheSYNC REC designates synchronous reproducing and writing (synchronousrecording) and this SYNC REC mode is selected when rewriting a part ofaudio data already recorded in the disc to other audio data or replacinga part of the audio data with other data (audio data indicating zero) toeliminate noise mixed therein.

At first, an operator reads the audio data from the disc 300 once toconfirm which part on the disc needs to be rewritten. Then the SYNC RECmode is selected after preparing a new signal to be replaced.

With reference to FIGS. 22A, 22B, and 22C and 23, the SYNC REC will beexplained. Firstly, head Nth blocks (1 to 3) and N+1 th blocks (4 to 6)of the blocks to be replaced are reproduced from the disc 300 by thepick-up 210 at 2.5 times speed with the timing shown in FIG. 22B (Steps341 and 342). The reproduced data is stored in the buffer memory 213 andthen read therefrom at standard speed to be output as a monitor outputwith the timing shown in FIG. 22A. When the N+1th blocks (4 to 6) arereproduced, the light pick-up unit 310 immediately moves to the headposition where the Nth blocks (1 to 3) are recorded at high speed (Step343). The new signal prepared is supplied to the magnetic head unit 230via the encoder 106, buffer memory 202 and head driver 232, and is newlyrecorded at the position where the Nth blocks (1 to 3) have beenrecorded at the timing shown in FIG. 22C. If the data needs to berewritten further, the light pick-up unit 310 moves to a position whereN+2th blocks (7 to 9) are recorded to reproduce the N+2th blocks (7 to9) (Step 345) and output them as monitor output. After that, the lightpick-up unit 310 returns to the recording head position of the previousblocks (4 to 6) to further record a new signal. The new recording signalmay be replaced while monitoring reproduced sound by repeating theaforementioned procedure.

Because the writing and reading of the audio data into/from the disc 300are carried out using the same clock, the SYNC REC operation involvedwith the synchronous reproducing and writing may be performed with onlythe single light pick-up unit 310.

The replacing new signal recorded in a recording medium beforehand isreproduced by an external reproducing device and is supplied to theencoder 106 of this apparatus. At this time, the timing of the positionand signal to be replaced may be taken using a known phase modifyingfunction. Further, it is possible to supply the new signal to thisapparatus so as to record audio data newly played by a player whilelistening to the reproduced monitor sound, without preparing the newsignal beforehand. Further, because the original recorded data isreproduced before rewriting data, the original audio data reproducedfrom the disc 300 may be supplied to the encoder 106 to be recordedafter implementing a desired process of changing sound quality, forexample.

FIG. 24 is a flowchart showing an exemplary process for registering thedisc identification code (disc ID). The disc ID is an identificationcode unique to the disc using numerals and marks or a combinationthereof, and is essential for managing discs. Numerical values inspecific digits generated using a table of random numbers may beappropriated within the apparatus when the disc is inserted into themain body of the apparatus, though it may be better to leave the settingof numerical codes to the user in order to improve management by theuser. FIG. 24 is a flowchart showing one exemplary process for realizingboth. When the disc 300 is inserted into the main body of the apparatus(Step 361), it is checked whether the disc ID has been registered or not(Step 362).

Because the disc ID is recorded in the sub-data area SA, whether thedisc ID has been registered or not may be checked by retrieving the datawithin this area. All the data in the sub-data area SA is read once andstored in the RAM 156.

When the disc ID is not being registered, how to specify a code to beregistered is checked (Step 363). When it is automatically set(automatically generated), a unique disc ID is specified from a table ofrandom numbers and is displayed on the display section 153 (Step 364).

When it is to be specified by means of external input, numbers inspecific digits are input from the keyboard and are displayed similarlyon the display section 153 (Step 365). The automatically set orspecified disc ID is registered (recorded) in the sub-data area SA bythe user (Step 366) by operating the keyboard.

When the disc ID has been already registered on the disc 300, a processfor reading the data is performed (Steps 362 and 370) and it is checkedwhether the registered disc ID is changed or not in the mode of the nextstep (Step 371). When it is not changed, the registering process ends asis. When a key-in is made to change it, the same processes in and afterStep 363 are carried out (Steps 372, 373, 374 and 375) and theregistering process ends.

The timing for writing the disc ID into the disc 300 may be adapted towrite it automatically when the disc is ejected, as well as writing itthrough keys operated by the user as described above. By doing so, arisk of forgetting to write the disc ID and of causing a trouble in themanagement of discs may be eliminated.

FIG. 25 shows an exemplary process when a protect mode for variousinformation accompanying the main data to be recorded in the sub-dataarea SA (hereinafter referred to simply as edit data and the like) isadopted.

Various edit data and the like for recording audio data on the disc 300,specifying an address of a cut-out point, and specifying the cross-fadeprocess are written and registered from the RAM 156 of the main body ofthe apparatus to the sub-data area SA of the disc 300 after finishingthe editing operations.

The audio data is read based on the edit data and the like thereafter.When recording the edit data and the like to the sub-data area SA, it isbest to inform the operator to prevent an erroneous recording when thedisc ID read in the main body of the apparatus and that of the disc 300to be recorded are different.

FIG. 25 shows one exemplary process for realizing this. When anexecution key is pressed to record the edit data and the like (Step381), the disc ID on the RAM 156 and the disc ID recorded in the disc300 are collated (Step 382). When they coincide and when the erroneouserase prevention claw 264 is not set at the position in the third step(Step 383), the edit data is recorded as is (Step 384).

Because a protect mode for the sub-data area SA is set when theerroneous erase prevention claw 264 is set at the third step, rewritingis inhibited even if the disc IDs coincide and an alarm is given to theuser at this time (Step 385). It is also possible to indicate on thedisplay section 153 that it is in the write protect mode.

Together with an indication that the disc IDs are inconsistent, thealarm is given similarly to the user (Step 386) when the disc IDs do notcoincide (Step 382).

After finishing these processes, it is checked whether an eject key isoperated or not (Step 387) and the disc 300 is ejected when the key isoperated (Step 388). Even if the key is not operated, the disc 300 isejected similarly when another key is pressed (Step 389), ending theprotected recording process of the edit data and the like.

The embodiment in FIG. 25 is a concrete example of the protect mode forthe edit data and the like when the execution key is pressed in anarbitrary timing when the editing operation is continued.

FIG. 26 shows specifically a concrete example of the protect mode forthe edit data and the like during the eject mode, regardless of whetherthe execution key is operated or not. What is different from FIG. 25 isthat a step which corresponds to Step 389 does not exist. This isbecause FIG. 26 shows a control program activated only when the ejectkey is operated. Therefore, corresponding reference numerals (391through 398) are used to denote steps that correspond to those in FIG.25 and an explanation thereof is omitted here.

Due to the protect process shown in FIG. 26, the edit data and the likewill not be recorded in a disc unrelated to the edit data nor will theedit data and the like be erased carelessly.

FIG. 27 shows an exemplary process for converting the absolute addressinto the time code. During editing, it is more convenient, causes lesserrors and is convenient also when sending out to an external device tomanage the absolute address as a time code in units of hour, minute,second and frame rather than as it is.

As described before, the absolute address is FM-modulated and isrecorded in the pre-groove 303 on the disc 300. The absolute address maybe detected by the address detecting circuit 216 and is transmitted tothe main CPU 400 via the servo CPU 500. The main CPU 400 converts theabsolute address into the time code in a specified format following theflowchart shown in FIG. 27.

To that end, the absolute address which is a block address is detectedat first (Step 411) as shown in FIG. 27 and constants for the conversionsuch as a word length BLKWD and a time code format data TCWD are set inthe next step (Step 412).

Because the word length and time code format information are written inthe sub-data area SA, the information remains in the disc 300 even whenthe power is turned off, exerting no influence on the reproducibility.

The word length BLKWD is a value dependent on the quantized number ofbits as shown in FIG. 28. The time code format data TCWD is a valuedetermined by a time code to be converted and sampling frequency asshown in FIG. 29. As the format of the time code, four types of formats(2 types of SMPTE and EBU and FILM) are used in this example as shown inFIG. 29.

The total count of frames TCFRM may be calculated by setting calculationconstants following the below expression (Step 413):

    TCFRM=(BLKADR×BLKWD)/TCWD

where, BLKADR is a present absolute address, BLKWD is the number ofwords per one block and TCWD is the number of words per one time codeframe.

Next, a start offset value of the absolute address TCOFST is added tocalculate the final total count of frames TCACT (Step 414).

This total count of frames TCACT is converted into the time codes ofhour, minute, second and frame and the converted output is displayed oroutput to an external device (Steps 415, 416 and 417).

FIG. 30 shows one example of a disc error processing flow. Disc error isbrought about when data cannot be written or read into/from the disc dueto dust and the like adhering to the surface of the disc.

In FIG. 30, this error check program starts when the disc 300 isinserted into the main body of the apparatus. First, the spindle motoris turned on, the focus and tracking operations are turned on and thelight pick-up unit 310 is enabled to seek the most inner periphery ofthe disc (head of the main data area MA) (Steps 421 to 423).

The data is read in this state to detect an error (Step 424). When atracking error cannot be eliminated even when tracking is controlled inthe tracking error detecting circuit 220 shown in FIG. 17, it is judgedto be abnormal (Step 425) and the address of the error at that time isregistered (Step 426).

The absolute address is read in a next step to check a CRC error (Steps427 and 428). CRC means an error correcting code. It is checked becausewhen a CRC error exists, an error correcting process cannot be correctlycarried out in the encoder 106, degrading the reproduction soundquality.

When the CRC error exists, an address counter (error counter) isinterpolated (operated) to increment count values of the error counter(Steps 429 and 430). When the count value (error count value) is morethan a specified value ("4" in the present embodiment), its absoluteaddress (error address) is registered (Steps 431 and 432).

When there is no CRC error, the error counter is cleared and continuityof the absolute address is checked next (Steps 433 and 434). When anabnormality is found in the continuity, an address of the error at thattime is registered in the same manner as described above (Step 432).After that, similar checking processes are carried out to the finalpoint of the disc similarly to the normal case (Step 435).

When the error check is completed by checking up to the outermostperiphery, whether an error exists or not is discriminated. When thereis no error, the end of the error check is displayed. When there is anerror, the disc 300 is cleaned and at the same time, the alarm isactivated and the error address is displayed. Then the error checkprocess is finished (Steps 436 through 438).

FIG. 31 is the flow of a process used when recording waveform data. Inthis example, a sampling for recording waveform data is started at thesame time as the start of recording of audio data (Step 441) and amaximum value "max" of the audio data is detected within a predeterminedperiod T (see FIGS. 14A and 14B) (Steps 442 and 443). The recordedaddress of the audio data that corresponds to the detected maximum valueis obtained and the maximum value of the audio data is stored in the RAM152 corresponding to the recorded address (Steps 444 and 445).

The process of detecting the maximum value and storing the detectedmaximum value in the RAM 152 is executed until the recording of theaudio data ends (Step 446). The waveform data stored in the RAM 152 isstored in the RAM 113 for sub-data and as the recording ends, it is sentto the recording/playback processing system 200 via the encoder 106 andstored in a predetermined position corresponding to the recorded addressin the sub-data area SA on the disc 300 by the head 230. Thus, therecording of the waveform data is completed (Step 447).

Because the audio data may be fully compressed if the predeterminedperiod t is set at around 0.1 seconds for example in this waveform datarecording process, a rough waveform envelope of the audio data may beobtained by reproducing the waveform data continuously. This is veryconvenient because it can be utilized for knowing the waveform duringediting.

FIGS. 32A and 32B show one example of a data record optimizing processfor effectively utilizing the recordable area of the disc. Duringediting of audio data, it is not always edited using all the audio datarecorded in the disc. Normally more audio data than necessary isrecorded and necessary takes are cut out therefrom and used. Due tothis, much more audio data than that after editing is initiallyrecorded.

In order to effectively utilize the area of the main data area MA intowhich audio data can be recorded, the area of the audio data which hasbecome unnecessary due to editing should be arranged as an empty area tobe able to record new audio data therein.

Such processing will be referred to as an optimizing processhereinafter. Because a data recording area before optimization is usedalso as a data recording area after optimization in the optimizingprocess, it is necessary to check whether audio data not used forediting operations exists or not in the data recording area beforeoptimization, before recording data after optimization. Otherwise theaudio data after optimization may be overwritten on the recording areaof non-used audio data to be used for the optimizing process to becarried out.

Explanation thereof will be made with reference to FIGS. 32A and 32B. InFIG. 32A, Si (i=1, 2, 3, . . . ) is audio data before optimization anddata area Ni shaded is audio data for cut-out (untreated data) usedduring editing wherein Ii is a cut-out starting point and Oi is acut-out ending point. It is assumed that the untreated data Ni is editedin the order of less number of i.

In FIG. 32B, Ei indicates an edit data pointer (editing point) and arelationship between the editing point Ei and the starting and endingpoints of the untreated data Ni may be represented as shown in FIG. 33.In FIGS. 32A and 32B, "W" is a pointer of recording point indicating adata writing point in the editing point E when carrying out theoptimizing process. "R" is a read pointer to the untreated data Nibefore optimization.

Because the untreated data Ni after optimization is overwrittensequentially on the audio data Si before optimization in the order ofless i, the untreated data N1 to be now optimized may be overwritten tothe audio data S1 while reading it without destroying it when thestarting point of the editing point E1 of the untreated data N1 is apoint q before optimization.

The same applies also to an editing point E2. In recording untreateddata N3, however, it cannot but be overwritten to untreated data N4 onthe audio data S1 (which is untreated data not yet used for theoptimizing process). In this case, the untreated data N4 is saved onceand then the untreated data N3 is overwritten on the untreated data N4.After overwriting the untreated data N3, the saved untreated data N4 isoverwritten on the audio data S1.

Thereafter, the optimizing process is carried out until the finalediting point after saving untreated data to be saved. The empty areaincreases as shown in FIG. 32B when the optimizing process is finished,so that the disc 300 may be more effectively utilized.

Considering the saving process, the optimizing process as shown in FIGS.34 and 35 is executed. The processing step continues from FIG. 34 toFIG. 35.

In the process flow shown in FIGS. 34 and 35, because all data recordedin the sub-data area SA are stored once in the RAM 113 or 156 (RAM 156is used in this embodiment), an empty area and edit data are read whileretrieving the data on the RAM 156 to store them again in the RAM 156(Steps 452 and 453). Thereafter, the recording point pointer W and editdata pointer E are initialized (Steps 454 and 455).

The explanation of each processing step thereafter will be madereferring to the concrete example shown in FIGS. 32A and 32B and FIG.33.

When initialization is completed, it is checked whether the contents ofthe edit data E (E1) is saved or not (Step 456). Because the edit dataE1 is not yet saved, the process moves to Step 457 to initialize a readpointer R of the untreated data N by the edit data E (Step 457). At thistime, the read pointer R is initialized so that it comes to the headaddress of the edit data E1.

Next, when the edit data E1 is not saved, it is checked whether audiodata of a certain length from the recording point pointer W is used asedit data thereafter or not (Step 460). Because no untreated data beforeoptimization corresponding to the edit data E1 exists, the audio datafrom the pointer R is written at a predetermined length from therecording point pointer W (Step 461).

The predetermined length of audio data means the data length determinedby the capacity of the temporary RAM 113, for example, which may be oneblock of edit data (composed of single or a plurality of takes) orshorter.

Next, it is checked whether the audio data of the read pointer R stillexists (Step 463). Because one item of edit data E1 cannot be completedwhen the audio data still exists, R and W are updated respectively toshift to the next pointer at the predetermined length to implement asimilar writing process (Steps 465 and 466).

When the audio data is overwritten until the data of the read pointer Rno longer exists (Step 463), the data area of the read pointer R isregistered as an empty area (Step 464). That is, the area of theuntreated data N1 in the audio data S1 is the empty area. New audio datamay be then recorded in the empty area.

As the overwriting of E1, which is one item of edit data, is completed,the editing point E is updated (Steps 467 and 468) and E2 becomes thenext editing point (see FIG. 33). Because the final position of theediting point E2 overwritten after optimization does not overlap theedit starting point I4 before optimization, the untreated data N2 isoverwritten on the area of the audio data S1 before optimization throughthe same steps as those of the edit data E1. Then the editing point E isupdated to E3.

While the saved content does not exist even at the editing point E3(Step 456), the audio data of predetermined length from the recordingpoint pointer W in the new editing point E3 (which corresponds to theuntreated data N4) is data to be used as edit data but not yet used foractual editing.

In this case, the process moves to Step 462 to save the untreated dataN4 from the recording point pointer W in the empty area on the disc 300.At the same time, the saved information is registered in the RAM 156.

Then, the untreated data N3 which corresponds to the editing point E3set in Step 457 is overwritten from the recording point pointer W (atthe head address of the editing point E3). As the untreated data N3 isoverwritten at the position of the untreated data N4 before optimizationin relation to the editing point E3, the editing point E is againupdated to E4.

Then, because it is found that the edit data E4 is saved in Step 456,the process moves to Step 458 this time to initialize the read pointer Rrelated to the untreated data N4 by using the save information describedabove, or to change to the head address of the editing point E4. Afterthat, the saved untreated data N4 is overwritten from the recordingpoint pointer R (Step 461).

Although a part of the untreated data N4 for the optimization overlaps apart of the untreated data N2 at this time in FIGS. 32A and 32B, itcauses no trouble in the overwriting process related to the untreateddata N4 because the data area of the untreated data N2 has been alreadyregistered as an empty area (Step 464).

The optimizing process as described above is carried out sequentially tothe final edit data while accompanying the saving process (Step 467) andis completed by finishing all of the edit data.

While the present invention has been specifically shown and describedwith reference to a preferred embodiment thereof, it will be understoodby those skilled in the art that the aforegoing and other changes inform and details can be made therein without departing from the spiritand scope of the present invention.

What is claimed is:
 1. An apparatus for recording data,comprising:receiving means for receiving digital audio signal inputdata, wherein said digital audio signal input data includes a series ofdigital values which represent the amplitude of an audio signal plottedover time; detecting means for detecting a maximum value of said digitalaudio signal input data that is received by said receiving means duringa predetermined time period, such that after a plurality of saidpredetermined time periods have elapsed, said detecting means hasdetected a plurality of maximum values, wherein each of said pluralityof maximum values corresponds to one of said plurality of predeterminedtime periods; memory means for temporarily storing said plurality ofmaximum values; and recording means for recording said digital audiosignal input data and said plurality of maximum values retrieved fromsaid memory means on a disc recording medium.
 2. The apparatus accordingto claim 1, wherein said disc recording medium has a first recordingarea for recording said digital audio signal input data and a secondrecording area for recording said plurality of maximum values.
 3. Theapparatus according to claim 1, further comprising:display meansconnected to said memory means so as to receive said maximum valuecorresponding to said predetermined time period for displaying saidmaximum value corresponding to said predetermined time period.
 4. Theapparatus according to claim 3, wherein said display means includes apredetermined number of display elements, such that said predeterminednumber of display elements equals a number of bits used to encode saiddigital audio signal input data, and wherein each of said displayelements corresponds to one bit used to encode said plurality of maximumvalues.
 5. The apparatus according to claim 1, furthercomprising:reproducing means for reproducing said plurality of maximumvalues from said disc recording medium; and means for supplying saidplurality of maximum values to said memory means to store therein.
 6. Amethod of recording data, comprising the steps of:receiving digitalaudio signal input data, wherein said digital audio signal input dataincludes a series of digital values which represent the amplitude of anaudio signal plotted over time; detecting a maximum value of saiddigital audio signal input data that is received in said receiving stepduring a predetermined time period, such that after a plurality of saidpredetermined time periods have elapsed, said detecting step hasdetected a plurality of maximum values, wherein each of said pluralityof maximum values corresponds to one of said plurality of predeterminedtime periods; temporarily storing said plurality of maximum values in amemory; and recording said digital audio signal input data and saidplurality of maximum values retrieved from said memory on a discrecording medium.
 7. The method according to claim 6, wherein said discrecording medium has a first recording area for recording said digitalaudio signal input data and a second recording area for recording saidplurality of maximum values.
 8. The method according to claim 6, furthercomprising the step of:displaying said maximum value corresponding tosaid predetermined time period.
 9. The method according to claim 8,wherein said displaying step utilizes a predetermined number of displayelements, such that said predetermined number of display elements equalsa number of bits used to encode said digital audio signal input data,and wherein each of said display elements corresponds to one bit used toencode said plurality of maximum values.
 10. The method according toclaim 6, further comprising the step of:reproducing said plurality ofmaximum values from said disc recording medium; and supplying saidplurality of maximum values to said memory to store therein.